At each stage of the product life-cycle, the key environmental impact categories relevant to the resource and the emission-related categories were investigated and evaluated. In terms of resources, factors such as the consumption of fossil resources, the amount of primary energy used and the use of nature are looked at. With respect to emissions, it is the criteria relating to climate change measured in CO2 emission, the particulate loading of the air and the eutrophication and acidification of soils and watercourses that are of interest. At present, the key environmental impact categories world-wide are emission of greenhouse gases, consumption of fossil resources and use of primary energy sources.

Main criteria: material and quantity

The results of the current study show clearly that the environmental impacts produced by a UHT milk packaging during the packaging life-cycle are determined first and foremost by the material from which the packaging is manufactured, and how much of the material was used. In this context, the current life-cycle assessment proved that the carton pack offers significant benefits − with respect to the use of resources and in terms of greenhouse gas emissions. The specific properties and the composite structure of the carton pack have a beneficial effect in nearly all of the environmental impact categories and especially in all the important ones like ‘Consumption of fossil resources’, ‘Use of primary energy sources’, and ‘CO2-emission/climate change’. Compared to 1-litre HDPE multilayer bottles (the UHT milk packaging solution that has the greatest market relevance in Europe after the carton pack), the carton pack generates 34 per cent less CO2, uses 56 per cent less fossil resources and consumes 30 per cent less primary energy; when compared to disposable PET bottles, these figures are 45 per cent for CO2 emissions, 57 per cent for fossil resources and 36 per cent for primary energy.

Above all, the resource-efficient use of raw paperboard, which is manufactured using a high fraction of renewable energy, and the low weight of a carton pack contribute significantly to its favourable environmental performance. Carton packs use significantly fewer fossil resources than HDPE and PET bottles, because the carton is manufactured by around 75 per cent from pulp fibres obtained from wood, a renewable resource. For this reason, in the 'Use of nature' environmental impact category, the carton pack lags behind the packaging solutions manufactured from fossil resource-based raw materials. In contrast to finite resources, however, with responsible forest management, there can be a constant supply of this renewable raw material. Another positive effect is that with sustainable forest management, wood is carbonneutral and therefore does not alter the CO2 balance of the atmosphere. The reason for this CO2- neutrality is that while they are growing, trees extract carbon dioxide from the atmosphere and store it. When they later burn or decay, they release exactly the same quantity of CO2 that they absorbed during their lifespan.